1. Field of the Invention
This invention generally relates to a bicycle rim. More specifically, the present invention relates to a bicycle rim having a seal structure facilitating use with a tubeless tire.
2. Background Information
Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle. One component that has been extensively redesigned is the bicycle wheel. Bicycle wheels are constantly being redesigned to be lightweight and more aerodynamic in design as well as to be simple to manufacture and assemble.
There are many different types of bicycle wheels, which are currently available on the market. Most bicycle wheels have a hub portion, a plurality of spokes and an annular rim. The hub portion is attached to a part of the frame of the bicycle for relative rotation. The inner ends of the spokes are coupled to the hub and extend outwardly from the hub. The annular rim is coupled to the outer ends of the spokes and has an outer portion for supporting a pneumatic tire thereon. Typically, the spokes of the bicycle wheel are thin metal wire spokes. The ends of the hub are each provided with a flange that is used to couple the spokes to the hub. In particular, holes are provided in the hub flanges. The wire spokes are usually bent on their inner end and provided with a flange that is formed in the shape of a nail head. The inner end is supported in one of the holes in one of the hub flanges. The outer ends of the spokes typically are provided with threads for engaging spoke nipples, which secure the outer ends of the wire spokes to the rim. In particular, the spoke nipples have flanges, which engage an interior surface of the rim. Alternatively, the spokes may be reversed, with the outer end having the nail head and the inner end having the threads for engaging spoke nipples, which secure the inner ends of the wire spokes to the hub.
The above types of wheels are typically designed for use with a tire and a separate tube used to inflate the tire. However, in recent years, some of the above types of wheels have been designed to be used with tubeless tires. Typically, these wheels utilize a seal mounted to the outer portion of the rim to prevent air leaks. While the use of a seal at the outer portion of the rim generally works well, the prior designs suffer from deficiencies.
Specifically, the use of a seal can allow leaking air even when the rim is relatively new, with certain rim and seal designs. Also, with some designs, the seal may work very well initially but the sealing effectiveness can be reduced, especially after prolonged use. Specifically, when the rider needs to replace the tire due to a puncture or excessive wear of the tire, the old tire needs to be removed and a new tire installed. One or more tire levers are typically used for this purpose. The tire itself and the tire levers can cause damage or wear to the seal during such replacement of the tire. Also, if a spoke needs to be replaced, the tire and the seal both have to be removed from the rim so the spoke can be replaced. Then, the seal and tire need to be reinstalled. Removal and reinstallation of the tire and/or seal can cause the seal and/or tire to be stretched, worn and/or damaged. Even if the seal and tire are not removed, normal riding can also cause wear to some of these prior seals. Specifically, sometimes these prior seals have ribs that support the tire during normal use. These ribs can become worn and/or damaged due to repeated small movements of the tire beads during riding. In any case, if these ribs become worn or damaged, performance of the tire may not be optimal. In other words, with these prior rim and seal designs the sealing effectiveness is not always optimal, especially after prolonged normal use and/or repeated removal and reattachment of the tire and/or seal. Also, with these prior rims, even if the sealing effectiveness is maintained after prolonged use, tire performance can be adversely affected due to wear or damage to the seal.
There are some rims with tubeless tires on the market, which do not include a plurality of holes in the outer portion for mounting the spokes, eliminating the need for an annular seal. Whiles these types of prior rims generally work well, these prior rims for tubeless tires suffer from other deficiencies. Specifically, these rims can be relatively expensive, inconvenient and complicated to manufacture and assemble. Also, these prior rims can be heavier than desired by some riders. More specifically, these prior rims often require a non-traditional spoke mounting structure at the rim, which contributes to the relative cost, complexity, weight, etc. of these types of rims.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved bicycle rim for use with a tubeless tire having an improved sealing structure. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.